diff --git a/src/infospace_bench/budget.py b/src/infospace_bench/budget.py
index db0cb29..163cb79 100644
--- a/src/infospace_bench/budget.py
+++ b/src/infospace_bench/budget.py
@@ -375,6 +375,75 @@ def _post_json(url: str, payload: dict[str, Any], timeout: float) -> None:
         response.read()
 
 
+def budget_show(root: str | Path) -> dict[str, Any]:
+    """Return the full per-infospace budget structure for inspection."""
+    root_path = Path(root)
+    plans_payload = _read_plans(root_path / PLANS_FILE)
+    usage_payload = _read_usage(root_path / USAGE_FILE)
+    variance = read_run_variance(root_path)
+    return {
+        "root": str(root_path),
+        "plans": {
+            "schema_version": plans_payload.get("schema_version"),
+            "pruned_count": plans_payload.get("pruned_count") or 0,
+            "snapshots": list(plans_payload.get("snapshots") or []),
+        },
+        "usage": {
+            "schema_version": usage_payload.get("schema_version"),
+            "runs": list(usage_payload.get("runs") or []),
+        },
+        "summary": variance,
+    }
+
+
+def budget_list_workspace(workspace: str | Path) -> list[dict[str, Any]]:
+    """Walk ``<workspace>/infospaces/*/output/budget/`` and roll up each infospace.
+
+    Missing budget directories are treated as zero, not as errors. Returns a
+    list of summaries in slug order.
+    """
+    workspace_path = Path(workspace)
+    infospaces_dir = workspace_path / "infospaces"
+    if not infospaces_dir.is_dir():
+        return []
+    rollups: list[dict[str, Any]] = []
+    for entry in sorted(infospaces_dir.iterdir()):
+        if not entry.is_dir():
+            continue
+        rollups.append(_summarise_infospace(entry))
+    return rollups
+
+
+def _summarise_infospace(root: Path) -> dict[str, Any]:
+    plans = read_plan_snapshots(root)
+    runs = read_usage_runs(root)
+    total_tokens = 0
+    total_cost_known = 0.0
+    total_cost_estimated = 0.0
+    last_run_at: str | None = None
+    for run in runs:
+        rollup = run.get("rollup") or {}
+        total_tokens += int(rollup.get("total_tokens") or 0)
+        total_cost_known += _coerce_float(rollup.get("total_cost_usd_known")) or 0.0
+        estimated = _coerce_float(rollup.get("total_cost_usd_estimated"))
+        if estimated is not None:
+            total_cost_estimated += estimated
+        completed_at = run.get("completed_at")
+        if isinstance(completed_at, str) and (last_run_at is None or completed_at > last_run_at):
+            last_run_at = completed_at
+    return {
+        "slug": root.name,
+        "root": str(root),
+        "plans_count": len(plans),
+        "runs_count": len(runs),
+        "total_tokens": total_tokens,
+        "total_cost_usd_known": round(total_cost_known, 6),
+        "total_cost_usd_estimated": round(total_cost_estimated, 6) if total_cost_estimated else None,
+        "last_run_at": last_run_at,
+        "latest_snapshot_id": plans[-1].get("snapshot_id") if plans else None,
+    }
+
+
 def read_run_variance(root: str | Path) -> dict[str, Any] | None:
     path = Path(root) / SUMMARY_FILE
     if not path.is_file():
diff --git a/src/infospace_bench/cli.py b/src/infospace_bench/cli.py
index 8eab20b..d93adf5 100644
--- a/src/infospace_bench/cli.py
+++ b/src/infospace_bench/cli.py
@@ -228,6 +228,19 @@ def build_parser() -> argparse.ArgumentParser:
     generate_from_source.add_argument("--max-chunks", type=int, default=0)
     generate_from_source.add_argument("--apply", action="store_true")
 
+    budget = sub.add_parser("budget", help="Inspect per-infospace budget and usage records")
+    budget_sub = budget.add_subparsers(dest="budget_command", required=True)
+    budget_list = budget_sub.add_parser(
+        "list",
+        help="Workspace rollup: one row per infospace with plan/run counts, tokens, cost",
+    )
+    budget_list.add_argument("workspace")
+    budget_show = budget_sub.add_parser(
+        "show",
+        help="Show the full plans/usage/summary payload for one infospace",
+    )
+    budget_show.add_argument("root")
+
     archive = sub.add_parser(
         "archive",
         help="Archive an infospace into artifact-store (durable, content-addressed)",
@@ -538,6 +551,14 @@ def main(argv: list[str] | None = None) -> int:
                     _write_json(plan_generation(infospace.root, stage=args.stage))
             else:
                 parser.error(f"Unhandled generate command: {args.generate_command}")
+        elif args.command == "budget":
+            from .budget import budget_list_workspace, budget_show
+            if args.budget_command == "list":
+                _write_json({"workspace": str(Path(args.workspace)), "infospaces": budget_list_workspace(Path(args.workspace))})
+            elif args.budget_command == "show":
+                _write_json(budget_show(Path(args.root)))
+            else:
+                parser.error(f"Unhandled budget command: {args.budget_command}")
         elif args.command == "archive":
             record = archive_infospace(
                 Path(args.root),
diff --git a/tests/test_budget_registry.py b/tests/test_budget_registry.py
index d2cb190..dd02690 100644
--- a/tests/test_budget_registry.py
+++ b/tests/test_budget_registry.py
@@ -623,6 +623,105 @@ def test_run_generation_never_fails_when_hub_is_down(tmp_path: Path, monkeypatch
     assert status["completed"] is True
 
 
+def test_budget_show_returns_full_per_infospace_structure(tmp_path: Path) -> None:
+    from infospace_bench.budget import budget_show
+    from infospace_bench.generator import run_generation
+
+    root = _build_infospace(tmp_path)
+    fixture = tmp_path / "responses.yaml"
+    _write_minimal_fixture(fixture)
+    plan_generation(root)
+    run_generation(root, fixture_responses=fixture)
+
+    payload = budget_show(root)
+
+    assert payload["root"] == str(root)
+    assert payload["plans"]["snapshots"], "plans must round-trip"
+    assert payload["usage"]["runs"], "usage runs must round-trip"
+    assert payload["summary"] is not None
+    assert payload["summary"]["snapshot_resolved"] is True
+
+
+def test_budget_list_workspace_rolls_up_multiple_infospaces(tmp_path: Path) -> None:
+    from infospace_bench.budget import budget_list_workspace
+    from infospace_bench.generator import init_generation_infospace, run_generation
+
+    book = tmp_path / "book.epub"
+    _write_three_chapter_epub(book)
+    fixture = tmp_path / "responses.yaml"
+    _write_minimal_fixture(fixture)
+
+    a = init_generation_infospace(tmp_path, book, "alpha", name="Alpha")
+    b = init_generation_infospace(tmp_path, book, "beta", name="Beta")
+    plan_generation(a.root, from_chapter=1, to_chapter=2)
+    plan_generation(b.root)
+    run_generation(a.root, fixture_responses=fixture)
+    # leave beta with a plan but no run, to verify partial rollups
+
+    rollups = budget_list_workspace(tmp_path)
+    by_slug = {item["slug"]: item for item in rollups}
+
+    assert {"alpha", "beta"} <= set(by_slug.keys())
+    assert by_slug["alpha"]["plans_count"] >= 1
+    assert by_slug["alpha"]["runs_count"] == 1
+    assert by_slug["alpha"]["last_run_at"] is not None
+    assert by_slug["beta"]["plans_count"] >= 1
+    assert by_slug["beta"]["runs_count"] == 0
+    assert by_slug["beta"]["last_run_at"] is None
+
+
+def test_budget_list_workspace_handles_missing_or_empty_directories(tmp_path: Path) -> None:
+    from infospace_bench.budget import budget_list_workspace
+    from infospace_bench.generator import init_generation_infospace
+
+    # No infospaces/ at all → empty list, not an error
+    assert budget_list_workspace(tmp_path) == []
+
+    # An infospace with no budget dir → rollup with zeros, not a crash
+    book = tmp_path / "book.epub"
+    _write_three_chapter_epub(book)
+    init_generation_infospace(tmp_path, book, "zero", name="Zero")
+
+    rollups = budget_list_workspace(tmp_path)
+    assert len(rollups) == 1
+    assert rollups[0]["slug"] == "zero"
+    assert rollups[0]["plans_count"] == 0
+    assert rollups[0]["runs_count"] == 0
+    assert rollups[0]["total_tokens"] == 0
+    assert rollups[0]["total_cost_usd_known"] == 0.0
+
+
+def test_budget_cli_list_and_show(tmp_path: Path) -> None:
+    from infospace_bench.generator import run_generation
+
+    root = _build_infospace(tmp_path)
+    fixture = tmp_path / "responses.yaml"
+    _write_minimal_fixture(fixture)
+    plan_generation(root)
+    run_generation(root, fixture_responses=fixture)
+
+    env = os.environ.copy()
+    env["PYTHONPATH"] = "src:/home/worsch/markitect-tool/src"
+
+    list_result = subprocess.run(
+        [sys.executable, "-m", "infospace_bench", "budget", "list", str(tmp_path)],
+        check=False, env=env, text=True, capture_output=True,
+    )
+    show_result = subprocess.run(
+        [sys.executable, "-m", "infospace_bench", "budget", "show", str(root)],
+        check=False, env=env, text=True, capture_output=True,
+    )
+
+    assert list_result.returncode == 0, list_result.stderr
+    assert show_result.returncode == 0, show_result.stderr
+    list_payload = json.loads(list_result.stdout)
+    show_payload = json.loads(show_result.stdout)
+    assert list_payload["workspace"] == str(tmp_path)
+    assert any(item["slug"] == "budget-test" for item in list_payload["infospaces"])
+    assert show_payload["plans"]["snapshots"]
+    assert show_payload["usage"]["runs"]
+
+
 def test_plan_cli_writes_snapshot(tmp_path: Path) -> None:
     root = _build_infospace(tmp_path)
     env = os.environ.copy()
diff --git a/workplans/IB-WP-0019-budget-and-usage-registry.md b/workplans/IB-WP-0019-budget-and-usage-registry.md
index dd19db8..60116e6 100644
--- a/workplans/IB-WP-0019-budget-and-usage-registry.md
+++ b/workplans/IB-WP-0019-budget-and-usage-registry.md
@@ -177,7 +177,7 @@ state_hub_task_id: "968bca1d-63ff-4818-83bb-ca314b1e633c"
 
 ```task
 id: IB-WP-0019-T06
-status: todo
+status: done
 priority: medium
 state_hub_task_id: "7cb34bfc-c562-4dda-a6d4-b44158644e19"
 ```